Side frame key assembly

ABSTRACT

A side frame key assembly for a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame comprises a one-piece angular key structure overlying a horizontal base portion of the frame and movably mounted in the key opening of the side frame and an extension spring underlying the horizontal base portion and releasably engaging spaced attachment portions of the key structure to complete a tie loop interlocking with the horizontal base portion to retain the key structure in position to react directly against the side frame when the roller bearing unit applies load force to the key structure.

United States Patent MacDonnell et al. Dec. 9, 1975 SIDE FRAME KEYASSEMBLY 3,831,531 8/1974 Wresch 105/221 K Inventors: Robert w.MacDonne, te; Otto 3,841,231 10/1974 Hhnsky 105/221 K A. Shander,Chicago Heights, both of I11. Primary ExaminerJOhn J. Love [73]Assignee: R. W. Mac Company, Crete, Ill.

[22] Filed: May 15, 1975 [57] ABSTRACT PP 577,736 A side frame keyassembly for a roller bearing unit Related Application Data mounted forrelative vertical movement in a pedestal- CO ti uaf t f S N 501067 A 27type side frame comprises a one-piece angular key lf g 0 structureoverlying a honzontal base portlon of the on frame and movably mountedin the key opening of the side frame and an extension spring underlyingthe hor- (g1 izontal base portion and releasably engaging Spaced [58]Fieid 221 R attachment portions of the key structure to complete a103/221 tie loop interlocking with the horizontal base portion to retainthe key structure in position to react directly [56] References Citedagainst the side frame when the roller bearing unit ap- UNITED STATESPATENTS plies load force to the key structure.

3,521,570 7/1970 Hasten, Jr. 105/221 K 15 Claims, 20 Drawing Figures US.Patent Dec. 9 1975 Sheet 1 of6 3,924,541

FIG.

FIG. 3

FIG. 6

Sheet 2 0f 6 U.S. Patent Dec.91975 Sheet 3 of6 3,924,541

10 FIG. 7

US. Patent Dec. 9 1975 Sheet 4 of 6 US. Patent Dec.91975 Sheet50f63,924,541

US. Patent Dec. 9 1975 Sheet 6 of6 3,924,541

PRIOR ART FIG. |8A

AOOQ x an: mwumhm LOAD (POUNDS X I000) FIG. |8B

an: mwmmkm LOAD (POUNDS X I000) SIDE FRAME KEY ASSEMBLY RELATEDAPPLICATION This application is a continuation-in-part of our pendingapplication Ser. No. 501,067 filed Aug. 27, 1974, now abandoned, andentitled Side Frame Key Assembly. The disclosure of said application ishereby specifically incorporated herein.

BACKGROUND OF THE INVENTION In the case of railway car trucks thatinclude pedestal-type side frames, it is conventional to provide a sideframe key mounted on the side frame to project through a key opening forretaining the roller bearing unit against accidental escape in the eventof a derailment. The conventional side frame key is a one-piece steelforging or casting bolted to a horizontal base portion of the side frameadjacent to the key opening. The mounting bolt arrangement is notdependable because the vibrations associated with normal operationsfrequently work the nut loose and allow the bolt to pop out. The keyeasily falls out once the bolt is gone.

Because of tolerance variations in the side frames the existingone-piece keys, even the keys with a top exten sion to engage above thekey opening and the keys with a reverse bend at the rear can onlytransmit the usual vertical loads by reacting against the holding powerof the bolt. Thus, the special bolted keys are still dependent on thebolt and the bolt is still subject to the vibration problem. Inaddition, the bolted keys are sometimes difficult to remove whenrequired for maintenance purposes.

SUMMARY OF THE INVENTION In accordance with the present invention animproved side frame key assembly is provided for easier and more securemounting on the side frame to solve the vibration problem, to transmitthe high shock loads associated with a derailment directly into the sideframe and to allow easy removability and replacement, therebyfacilitating the truck maintenance operations.

The improved key assembly for preventing accidental escape of a rollerbearing unit mounted for relative vertical movement in a pedestal-typeside frame that includes a vertical side wall having a horizontal baseportion projecting away from the roller bearing unit, said vertical sidewall having a generally rectangular key opening facing a lowerperipheral region of the roller bearing unit, the key opening borderedby a front base comer portion and a top corner portion of the side wall,said key assembly comprising an angular body having a retainer portionto project outwardly of the key opening and border the lower peripheralregion of the roller bearing unit and having a rearwardly projectinglever portion to.overlie the horizontal base portion, said bodypresenting direct keying means to fulcrum against the front base cornerportion and remote keying means to engage a second side frame portionspaced from the front base comer portion, said body having spacedattachmentportions, and locking loop means to underlie the horizontalbase portion and engage said attachment portions to complete a .tie loopinterlocking with the horizontal base to retain the body in movablerelation to enable both said keying means to react directly against theside frame when the roller bearing unit applies load force to theretainer portion.

In the presently preferred embodiments, the locking loop means is in theform of a tension spring that engages the key structure adjacentopposite extremities of the horizontal base portion of the side frame.The spring is not further stressed, once the key structure engages theside frame in load transmitting relation.

In one form, the one-piece key structure is elongated to present, at oneend, a direct keying means in the form of a retainer portion thatfulcrums on a front base corner portion bordering the bottom of the keyopening and to present, at the other end, a remote keying means in theform of a reverse bend portion that interlocks with a rear base cornerportion of the side frame. The locking spring is permanently attached toa front hook portion that depends from the retainer and is releasablyattached to a rear hook that depends from the reverse bend position.

The key structure is also provided with a depending stub that seats inthe existing bolt hole in the base to retain the mounted position of thekey body.

In other forms, the one-piece key body includes either a top extensionportion that serves as a remote keying means that directly engages a topcorner portion bordering the key opening or lateral extensions thatserve as remote keying means that directly engage rear edges of the sideframe. In these forms, the key includes the direct keying means in theform of a retainer portion that fulcrums on a front base corner portionbordering the bottom of the key opening and a lever portion that carriesa depending rear hook for releasably securing a locking spring that ispermanently attached to a front hook that depends from the retainerportion.

The lever portion may be either in the form of a reverse bend tointerlock with the rear base corner portion or in the form of adepending flange located alongside the rear base comer portion. Adepending stub seating in the bolt hole in the base again serves toretain the mounted position of the key body.

The side frame key assembly is arranged to be applied in the train yardthe same as brake shoes or other yard type repairs, thus eliminating theexpense of shopping the car as is now the case. Equally important is thefact that the problem of missing roller bearing keys should gradually beeliminated since key replacements can now be made as part of the trainyard program.

Eliminating the need for mounting bolts reduces the installation laborboth as respects applying the bolts and as respects removing or burningoff the bolts when changing wheels.

The locking spring feature keeps the key structure in proper position atall times to positively protect against vibration effects and its designeliminates the need for special handling tools.

The strength of the preferred side frame key embodiments and theresilient mounting relationship achieved for parts that are easy toremove and replace and the fact that the spring is not subjected to theactual load forces insures a long useful life.

Other features and advantages of the invention will be apparent from thefollowing description and claims, and are illustrated in theaccompanying drawings which show structure embodyingfeatures of thepresent invention and the principles thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings forming apart of the specification and in which like numerals are employed todesignate like parts throughout the same:

FIG. 1 is a fragmentary, transverse sectional view, showing aconventional pedestal-type side frame and roller bearing unit inconjunction with a side frame key assembly of this invention employing aone-piece angular key structure.

FIG. 2 is an end view showing the key assembly in mounted position.

FIG. 3 is a bottom plan view of the angular key structure.

FIG. 4 is a transverse sectional view, similar to FIG. 1, showing amodified embodiment.

FIG. 5 is an end view of the embodiment of FIG. 4.

FIG. 6 is a transverse sectional view similar to FIG. 4 and showinganother embodiment.

FIG. 7 is a transverse sectional view similar to FIG. 6 showing anotherembodiment.

FIG. 8 is an end view of the embodiment of FIG. 7.

FIG. 9 is a transverse sectional view similar to FIG. 1 showing astreamlined embodiment.

FIG. 10 is an end view of the embodiment of FIG. 9.

FIG. 11 is a bottom plan view of the embodiment of FIG. 9.

FIG. 12 is a transverse sectional view illustrating insertion of theFIG. 9 key into the key opening.

FIG. 13 is a transverse view illustrating engagement of the spring tointerlock the FIG. 9 key in mounted position.

FIG. 14 is a transverse sectional view similar to FIG. 1 and showinganother streamlined embodiment.

FIG. 15 is a bottom view of the key shown in FIG. 14.

FIG. 16 is an end view of the embodiment of FIG. 14.

FIG. 17 is a fragmentary section showing a spring provided with a wearsleeve.

FIG. 18 is similar to FIG. 14, but shows a prior art key.

FIGS. 18A and 1813 give test data on the prior art keys of FIG. 18.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings aconventional railway car truck arrangement is shown as including apedestaltype side frame designated generally at 10 which is supported ona roller bearing unit 11. The side frame has vertical pedestal wallsflanking the roller bearing unit 11 and normally allowing relativevertical movement between the roller bearing unit and the side frame foraccomodating disassembly. The side frame wall 12 has a conventional keyopening 13 and is shown to terminate in a horizontal base portion 14that is typically provided with a hole 15 for an anchor bolt such as isused with prior art type side frame keys.

The improved side frame key of this invention uses a one-piece angularkeying structure 16 in conjunction with a locking loop means that isshown here in the form of a tension spring 17. The spring 17 underliesthe base 14 and is connected to spaced portions of the key structure toform a tie loop that interlocks with the base portion 14. The keyingstructure is mounted for limited movement in the key opening 13 and hasdirect and remote keying means l8, 19, positioned for direct engagementwith spaced apart portions of the side frame to transmit load forcesdirectly into the side frame. The direct keying means 18 serves as theactual bearing contacting and retaining portion and is freeto fulcrum onthe front base corner portion 14F. The remote keying means 19 is in theform of a reverse bend portion that embraces and interlocks around therear base corner 14R to transmit loads upwardly into the base by 4reason of the fulcrum action of the direct keying means Limited movementof the keying means 18, 19, as provided by the action of the lockingspring 17 insures that the keying structure remains in proper positionin the key opening 13 and establishes direct load transmittingengagement in spite of numerous dimension and profile variances in thedifferent base walls and key openings that are encountered. Load forcesapplied to the key structure in connection with its function ofretaining the roller bearing unit 11 are transmitted by fulcrum actionof the direct keying means 18, the primary load being transmitteddirectly into the front base corner portion 14F and the reaction loadbeing transmitted through the remote keying means into the rear basecorner portion 14R.

It should be noted that the load transmitting action of the angularkeying structure is insured by the presence of the locking spring 17,which permits simultaneous engagement at both the front and rear basecorner 10- cations; however, the locking spring is not itself subjectedto the actual load forces. In the illustrated embodiments the lockingspring 17 is in the form of a stainless steel wire extension springhaving a connecting loop 17F at the front end and a connecting loop 17Rat the rear end. The front loop 17F is permanently secured in theeyehole of a front hook portion 18H that depends centrally from theretainer portion. The rear loop 17R is releasably engaged upon a rearsecurement hook 19H carried at the extremity of the remote keying means19 and located beneath the base 14 to provide adequate clearance for thespring. When the spring 17 is in place it is in an elongated tensionstate, and applies a holding force of about 50 pounds to retain the keystructure in proper position.

During normal operating conditions the usual vibration effectsencountered will not dislodge the spring 17 nor will the spring allowvibrations to disengage the key structure from its proper position andorientation. Thus, when load froces are applied, whether vibrationeffects are present or not, both the direct and the remote keying meansare in simultaneous engagement with the base to distribute the loaddirectly into the front and rear base corners of the side frame.

The one-piece angular key structure 16 has a substantially plate-like,full length horizontal main wall 16M overlying the base to serve as alever portion carrying the remote keying means in contact with the rearbase corner and carrying the forwardly projecting retainer portion 18 inposition to border the lower peripheral region of the roller bearingunit 11 to prevent the roller bearing from dropping out of the pedestalwindow of the side frame. The angular key structure 16 may be of anyconfiguration suitable for casting or forging. In the illustratedembodiment, the main wall 16M has a tapering plan profile to merge atthe front with the relatively wide retainer portion 18 and to merge atthe rear with the relatively narrow u-shaped portion 19. The region ofthe merger of the main wall 16M with the retainer presents downwardlyfacing shoulderlSD that serve as the direct keying means that is tofulcrum on the front base corner 14F. The retainer portion has inwardlyfacing shoulders 181 spaced from the corner portion 14F to permitinsertion of the key body. The retainer portion presents a contact facethat is generally arcuate in side profile to provide a broad contactarea in close clearance with the roller bearing unit. The main wall 16Mhas a beveled upper face to present a peaked, gently sloping top. Themain wall has a concave central underface region that is provided with adepending stub 168 that fits loosely in the existing bolt hole to retainthe desired key orientation.

It should be noted that the key structure seats in snug, limitedclearance relation upon the side frame base and is positively seated bythe action of the spring to maintain a positive mechanical interlockthat is totally resistant to vibration effects while allowing the keystructure to adapt to variances at the mounting location as required toestablish simultaneous load transmitting engagement for both the directand the remote keying means.

The procedure for mounting the side frame key assembly in installedposition as shown in FIG. 1 is simple. The key body 16, with the spring17 attached at the front, is inserted by feeding the free end of thespring through the key opening 13 from the rear side followed by the keystructure which is held in the right hand with its retainer and tippedslightly upwardly. When the retainer projects partly through the keyopening and the stub 16S passes over the rear base corner, the keystructure is progressively rotated back to horizontal position andsettled into place. The stub 165 contacts the top surface of the basewhen the key is forwardly inclined during insertion or removal. Itsbottom face is rearwardly bevelled to facilitate insertion and removal.There is sufficient clearance to permit rapid insertion but the movementsequence must be accurate because the clearances are close. The lockingspring 17 is then extended sufficiently to draw its rear loop 17R overthe securement hook 19H. A pointed bar is suitable for the purpose.

A modified embodiment is shown in FIGS. 4 and 5 wherein the key body isessentially the same, as described, but in addition, the main body 16Mof the onepiece key structure is shown as including an auxiliary remotekeying means in the form of a pair of integral top extensions 16Tarranged on opposite sides of the key opening in position to contact thelateral corner portions 14L and/or the top corner portion 14T of the keyopening 13. In FIG. 5 a slight clearance is shown between the extensions16T and the corner portions 14L, 14T because the variances in the keyopening and base dimensions are such that it is not possible to assuresimultaneous contact with both of the direct and remote key means 18, 19and, in addition, of the auxiliary remote keying means.

The extensions 16T are provided as a temporary interlock in the eventthe remote keying means 19 were broken, but under these conditions thespring would necessarily be disengaged and the key would be subject toloss.

Another modification is shown in FIG. 6 wherein a single, centrallylocated integral top extension 16T' is provided on the main body to actas a primary remote keying means operating in conjunction with thedirect keying means 18 to simultaneously engage spaced portions of theside frame in load transmitting relationship In FIG. 6, an angled rearportion 19 extends alongside the rear base corner and terminates in arear securement hook 19H that receives the rear loop 17R of the tensionspring. The rear portion 19' does not provide an interlock and thus maybe of reduced thickness and width. The rear portion is only subjected tothe spring load and is movable to enable the top extension and thedirect keying means 18 to establish simultaneous engagement in spite ofvariances in the key open- 6 ing and base dimensions that arenecessarily encountered.

Another modification is shown in FIGS. 7 and 8 wherein a pair ofintegral lateral extensions 16L are provided on the main body 16 to actas remote keying means to engage rear edge portions of the side frame.

As best seen in FIG. 7 and angled rear portion 19" extends in clearancerelation to the rear base corner portion and the retainer portion 18"has a streamlined profile to project from the key opening 13 inclearance relation to the front base corner portion 14F.

The main body 16 has a depending stub or locator post that fits in thehole 15 in limited clearance relation to locate the mounted position ofthe key body.

The extension spring 17 as shown in installed position, has a front loop17F engaged in the eye of a depending hook portion 1811" that dependsfrom the retainer portion 18 in clearance relation to the front cornerportion and a rear loop 17R engaged in the depending rear hook 1911 thatis carried at the rear of the lever portion in clearance relation to therear corner portion. The extension spring 17 has a pull loop 17L at itsrear end that is engageable by a pointed bar or screw driver forextending the spring sufficiently to engage the rear loop 17R over therear hook 19H" for locking the key in place.

The spring 17 would allow the key to shift sideways but such movementsare limited by engagement of the locator post in the hole.

A further embodiment of the invention is shown in FIGS. 9 to 13, thisembodiment being suitable for manufacture as a steel casting of M-20lGrade B material or as a casting of alumin um-zinc-magnesium alloy or asa carbon steel forging of M-126, Grade A material.

The key assembly, as shown in its installed position in FIG. 9, 10 and11 has a key body 116 that includes a rearwardly extending lever portionterminating in a reverse bend portion 119 that extends in clearancerelation around the rear base corner portion 14R and terminates in adepending hook 11911 and has a forwardly projecting streamlined retainerportion 118 that has a depending hook portion 11811 in substantialclearance relation to the front base corner portion 14F and providing aspring mounting eye.

The key body 116 includes a central depending stub 1168 that tits inlimited clearance relation in the bolt hole 15 to locate the mountingposition of the key.

The retainer portion 118 has a flat downwardly facing surface to serveas direct keying means that fulcrums on the front corner 14F and thereverse bend portion 119 has forwardly and upwardly facing surfaces toserve as remote keying means that interlocks with the rear comer 14R.

The extension spring 117 has a front loop 117F engaged in the hookportion 1181i and a rear loop 117R engaged in the hook portion 119H toform a tie loop interlocking with the horizontal base 14 to retain thekey body in movable relation and enable both keying means to reactdirectly against the side frame when the roller bearing unit 11 appliesload force to the retainer portion.

Limited movement of the key body is accomodated by the provision ofmounting clearances sufficient to allow for any side frame tolerancevariations that may be encountered. The spring readily accomodates suchlimited movement so that the load forces do not act upon the spring butare transmitted by the key directly into the side frame.

At best seen in FIG. 11, the spring includes a pull loop 1l7L at therear to facilitate engagement of the spring with the key.

The insertion and engagement of the key is illustrated in the sequenceviews of FIGS. 12 and 13. The key is oriented as shown in FIG. 12 tofeed the spring 117 and the retainer portion 118 forwardly through thekeyhole. The stub 116$ contacts the base during insertion and may bebeveled to facilitate entry into the bolt hole 14 to the FIG. 13position, wherein the stub is in limited clearance in the bolt hole.

In this embodiment, the streamlined configuration of the retainerportion 118 permits the depending hook I 18H to be longer to locate thespring more nearly horizontal and more directly aligned with the rearhook 1191-1. The intermediate turns of the spring react against theunderface of the base 14 to hold the key in its seated position asillustrated. Larger diameter spring wire stock can be utilized toachieve a snug fit against the base and to accommodate any wearresulting from contact between the spring and the base.

With the key in place as shown in FIG. 13, the spring interlock issecured by inserting a pointed bar B through the pull loop 117L to wedgethe bar against the lower external corner on the reverse bend portion 119. The bar is swung counter-clockwise to force the rear spring loop117R over and onto the hook portion 119H. When the spring is seated, thebar is withdrawn and the key is locked in position as shown in FIG. 9.

For removal, the bar is inserted through the pull loop, wedged againstthe key and swung counter-clockwise and then pulled downwardlysufficiently to free the loop 117R from the the hook 1191-1. Theretainer portion of the key is then lifted upwardly until the stub 116Sclears the bolt hole 15 to allow the key to be pulled back.

A comparative test of a key constructed according to FIG. 1 with a keyconstructed according to FIG. 9, where both keys were subjected tostatic vertical loading applied to the retainer portions, showed thatthe streamlined embodiment carried about per cent greater load than didthe FIG. 1 embodiment prior to fracture. In both tests, the fractureoccurred at the transverse region of the key overlying the front corner14F of the base.

The tested keys were constructed substantially to the proportions shownin FIGS. 1 and 9 where the scale is determined on the basis that thetotal end to end key length is 6 inches. It is believed that thestreamlined embodiment of FIG. 9 may provide greater strength againstvertical loading of the retainer portion because the streamlinedretainer region merges with the main body without creating any localizedstress pattern such as the shoulder 181 in FIG. 1 would introduce.

It should be noted that the disclosed embodiment of FIGS. 1 and 9present a retainer portion having a bearing contact surface that extendsalong a 45 angle. The bearing contact surface may be slightly curved orsubstantially straight and the 45 angle enables the retainer toestablish essentially the same clearance relation to the bearing for anentire range of bearing sizes.

A preferred embodiment is shown in FIGS. 14 to 16 where the key is shownin proportion on a scale where the total end to end key length is 6inches.

In this embodiment, the key body 216 is provided with integral sidewings 216W in place of the location post. The wings have a span of 2%inches to fit with limited clearance between the pedestal side walls tocooperate with the hood 219 in maintaining the desired key alignment.

The omission of the locating post enhances the keys ability to fit allexisting truck applications, even including rebuilt trucks where thebearing is located at a slightly lower position relative to the sideframe.

The bearing contact surface is again shown at a 45 angle and at aposition to establish substantially uniform clearance for all bearingsizes.

Thus, with the retainer portion 218 being streamlined and with thelocating post being eliminated, the key shown in FIGS. 14 and 16 is ofmaximum strength for resisting vertical loads and is of maximumversatility to fit all side frame conditions and achieve substantiallyuniform clearance for various sizes of bearings and wheels.

An improved spring assembly for use in any of the disclosed embodimentsis shown in FIG. 17, wherein an extension spring 17 is shown providedwith a wear sleeve 17W, preferably of polyurethane or other suitable.material, to accommodate contact and vibration effects between theintermediate coils of the spring and the side frame base.

FIG. 18 shows a key constructed exactly to the proportions of the keyshown in FIG. 5 of US. Patent No. 3841231 on the basis that the flange50 is 3 A inches by inches in size. The only difference between the FIG.18 key and the prior art key of US. Pat. No. 3841231 is the provision ofa horizontal top surface on the retainer to allow for convenientapplication of vertical loads.

Two samples of the FIG. 18 key were made and tested to determine theeffect of the hook for preventing the bolt from being subjected to anystress due to vertical loads applied to the retainer portion.

Strain gauges were provided at the locations labeled 1, 2, 3 and 4. Thegauge at location 1 gives readings for the hook stresses and these arerepresented by curve 111 in FIG. 17A. The gauges 2 and 3, together, givethe readings of the average loading on the bolt. The gauge 4 givesreadings to show changes in stress at the hook.

In each test, the key was secured by torquing the nut and bolt to 250foot-pounds to provide preload in accordance with A.A.R. requirements.

Test results (based on strain gauge readings) on one sample are given inthe graph of FIG. 18A where the curve B shows the load conditions at thebolt and the curve H shows the load condition at the hook.

Test results on a second sample are given in the graph of FIG. 18B whereB shows the load condition at the bolt and H shows the load condition atthe hook.

It appears that the bight-like form of the hook is unable to preventloading of the bolt because the initial hook engagement is necessarilyreduced when the bolt and nut assembly is given the requiredpre-loading.

Thus, while preferred constructional features of the invention areembodied in the structure illustrated herein, it is to be understoodthat changes and variations may be made by those skilled in the artwithout departing from the spirit and scope of the appended claim.

What is claimed is:

1. A side frame key assembly for preventing accidental escape of aroller bearing unit mounted for relative vertical movement in apedestal-type side frame that includes a vertical side wall having ahorizontal base portion projecting away from the roller bearing unit,said vertical side wall having a generally rectangular key openingfacing a lower peripheral region of the roller bearing unit, the keyopening bordered by a front base corner portion and a top corner portionof the side wall, said key assembly comprising angular keying structureoverlying the horizontal base portion and freely movable in the keyopening and having direct keying means to fulcrum against said frontbase corner portion and remote keying means for abutment against aspaced apart side frame portion, said key structure having a rearwardlyprojecting lever portion overlying said base portion and an outwardlyprojecting retainer portion bordering the lower peripheral region of theroller bearing unit, and locking loop means underlying the horizontalbase portion and releasably engaging between spaced attachment portionsof the key structure to complete a tie loop embracing the horizontalbase portion to retain the key structure in movable relation to enableboth said keying means to react directly against the side frame when theroller bearing unit applies load force to the retainer portion.

2. A side frame key assembly as defined in claim 1 wherein one of theattachment portions depends from the retainer portion and the otherattachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring.

3. A side frame key assembly as defined in claim 1 wherein said keystructure includes a depending central stub for seating in an existingbolt hole in said base portion to determine the mounting position of thekey body. i i

4. A side frame key assembly as defined in claim 1 wherein said leverportion carries a rear reverse bend portion to interlock with a rearbase corner portion of the side frame and serve as the remote keyingmeans.

5. A side frame key assembly as defined in claim 4 wherein said leverportion includes a depending central stub for seating in an existingbolt hole in said base portion to determine the mounting position of thekey body.

6. A side frame key assembly as defined in claim 4 wherein one of theattachment portions depends from the retainer portion and the otherattachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring.

7. A side frame key assembly as defined in claim 4 wherein one of saidattachment portions depends from the retainer portion and the otherattachment portion 10 depends from the reverse bend portion and whereinsaid locking loop means is an extension spring.

8. A side frame key assembly as defined in claim 4 wherein said leverportion carries a top extension in clearance relation to the top cornerportion of the key opening to act as an auxiliary interlock.

9. A side frame key assembly as defined in claim 1 wherein said leverportion carries a top extension to serve as the remote keying means andengage with the top corner portion of the key opening simultaneouslywith the engagement of the direct keying means with the base cornerportion.

10. A side frame key assembly as defined in claim 1 wherein said leverportion carries lateral extensions to serve as the remote keyingmeans'and engage with rear edge portions of the side framesimultaneously with the engagement of the direct keying means with thebase corner portion. and wherein one of said attachment portions dependsfrom the retainer portion and the other attachment portion depends fromthe lever portion and wherein said locking loop means is an extensionspring.

11. A side frame key assembly as defined in claim 1 wherein said leverportion includes laterally projecting wings to fit with limitedclearance relation in the side frame for maintaining key alignment.

12. A side frame key assembly as defined in claim 1 wherein one of theattachment portions depends from the retainer position and the otherattachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring reacting upwardly against saidbase portion to bias said keying structure downwardly against saidhorizontal base portion.

13. A side frame key assembly as defined in claim 1 1 wherein one of theattachment portions depends from the retainer portion and the otherattachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring reacting upwardly against saidbase portion to bias said keying structure downwardly against saidhorizontal base portion.

14. A side frame key assembly as defined in claim 7 wherein saidretainer portion is of streamlined configuration and said extensionspring reacts upwardly against said base portion to bias said keyingstructure downwardly against said horizontal base portion.

15. A side frame key assembly as defined in claim 12 wherein saidextension spring is disposed within a wear sleeve of non-metallicmaterial.

1. A side frame key assembly for preventing accidental escape of aroller bearing unit mounted for relative vertical movement in apedestal-type side frame that includes a vertical side wall having ahorizontal base portion projecting away from the roller bearing unit,said vertical side wall having a generally rectangular key openingfacing a lower peripheral region of the roller bearing unit, the keyopening bordered by a front base corner portion and a top corner portionof the side wall, said key assembly comprising angular keying structureoverlying the horizontal base portion and freely movable in the keyopening and having direct keying means to fulcrum against said frontbase corner portion and remote keying means for abutment against aspaced apart side frame portion, said key structure having a rearwardlyprojecting lever portion overlying said base portion and an outwardlyprojecting retainer portion bordering the lower peripheral region of theroller bearing unit, and locking loop means underlying the horizontalbase portion and releasably engaging between spaced attachment portionsof the key structure to complete a tie loop embracing the horizontalbase portion to retain the key structure in movable relation to enableboth said keying means to react directly against the side frame when theroller bearing unit applies load force to the retainer portion.
 2. Aside frame key assembly as defined in claim 1 wherein one of theattachment portions depends from the retainer portion and the otherattachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring.
 3. A side frame key assemblyas defined in claim 1 wherein said key structure includes a dependingcentral stub for seating in an existing bolt hole in said base portionto determine the mounting position of the key body.
 4. A side frame keyassembly as defined in claim 1 wherein said lever portion carries a rearreverse bend portion to interlock with a rear base corner portion of theside frame and serve as the remote keying means.
 5. A side frame keyassembly as defined in claim 4 wherein said lever portion includes adepending central stub for seating in an existing bolt hole in said baseportion to determine the mounting position of the key body.
 6. A sideframe key assembly as defined in claim 4 wherein one of the attachmentportions depends from the retainer portion and the other attachmentportion depends from the lever portion and wherein said locking loopmeans is an extension spring.
 7. A side frame key assembly as defined inclaim 4 wherein one of said attachment portions depends from theretainer portion and the other attachment portion depends from thereverse bend portion and wherein said locking loop means is an extensionspring.
 8. A side frame key assembly as defined in claim 4 wherein saidlever portion carries a top extension in clearance relation to the topcorner portion of the key opening to act as an auxiliary interlock.
 9. Aside frame key assembly as defined in claim 1 wherein said lever portioncarries a top extension to serve as the remote keying means and engagewith the top corner portion of the key opening simultaneously with theengagement of the direct keying means with the base corner portion. 10.A side frame key assembly as defined in claim 1 wherein said leverportion carries lateral extensions to serve as the remote keying meansand engage with rear edge portions of the side frame simultaneouSly withthe engagement of the direct keying means with the base corner portion,and wherein one of said attachment portions depends from the retainerportion and the other attachment portion depends from the lever portionand wherein said locking loop means is an extension spring.
 11. A sideframe key assembly as defined in claim 1 wherein said lever portionincludes laterally projecting wings to fit with limited clearancerelation in the side frame for maintaining key alignment.
 12. A sideframe key assembly as defined in claim 1 wherein one of the attachmentportions depends from the retainer position and the other attachmentportion depends from the lever portion and wherein said locking loopmeans is an extension spring reacting upwardly against said base portionto bias said keying structure downwardly against said horizontal baseportion.
 13. A side frame key assembly as defined in claim 11 whereinone of the attachment portions depends from the retainer portion and theother attachment portion depends from the lever portion and wherein saidlocking loop means is an extension spring reacting upwardly against saidbase portion to bias said keying structure downwardly against saidhorizontal base portion.
 14. A side frame key assembly as defined inclaim 7 wherein said retainer portion is of streamlined configurationand said extension spring reacts upwardly against said base portion tobias said keying structure downwardly against said horizontal baseportion.
 15. A side frame key assembly as defined in claim 12 whereinsaid extension spring is disposed within a wear sleeve of non-metallicmaterial.